See my explanation above.

Here is the exact time given "At a recent session", so we should use past simple. The decision was made on the certain date. The decision process does not continue at this moment.
It is like saying "On Monday, the French government decided ..."

The answer is B because the word "has" doesn't have a place in the underlined part of the sentence since the author speaks of a past incident, "in a recent session".

I think that both verbs "decide and need" should be in the same tense. Why in B, need is in the present? Please explain on this problem. I chosen B first, but later I chosen A for this reason.

OA is B

Present Perfect:

Action Started.............continue.....................Present.

=> Means an action started in the past and continued to present. There will be an on going operation or action.

In the recent session, a decision was taken. There is no ongoing action here. Some took the decision. Then what? anything else up to present? No. Means there is no ongoing action. So, we need to use past simple tense.

Hope that helps.

why "Has Decided" options cancelled out vs. "Decided"?

Although this post has been here for a very long time I am not quite agreeing with the explanation.
Present Perfect has not only the usage as described above, the present perfect is also used for actions / events that started in the past, finished at some point but still have an impact on the current present / future.
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Can someone please explain why option A is incorrect? We can use present perfect if the effect of the action is still ongoing.
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After reading this question, I somehow got correct ans. and reading below explanations, I think I can put mine, if it helps!!!
yeah, the concept is right that the action when started in past but also having the impact in present will have the present perfect tense, but the use of Recent and Past perfect tense will make it redundant so that's why Simple past tense is used for eg:

Case 1: In the recent match, India won the match by 20 runs.

Case 2: India has won the match by 20 runs.

Both conveys the same meaning I hope...

ERROR ANALYSIS -

1) Please note that proper timing and place is given in the sentence, so simple past tense needs to be used

ANSWER CHOICE ANALYSIS -

A) Simple past needs to be used
B) CORRECT
C) Simple past needs to be used
D) Too wordy compared to B
E) Simple past needs to be used

HAS is used to describe an event happened recently. As the sentence itself is saying that the session is a recent one, usage of HAS will lead to redundancy.

Option A, C, and E will go off. Option D is distorting the meaning. Hence Option B is right

Isnt this a case of subjunctive verb? ... decided that Paris needs .... the verb should be plural here.

I misclicked A but meant B lol

A, C, and E can be eliminated since "has decided" should be an action not a thing possessed by "the French Government"

D Similar issue to A, B and C. "of" is incorrectly floods the subject with "a need". Generally wrong.

B is the most correct and concise.