Based on controlled experiments involving laboratory animals, any new

Aren't proved and proven, both acceptable forms of past participle of prove - |Prove proved proved/proven|
Does GMAT only consider "Proven" correct?

Even if so, first conditional sentence in passive voice can still use "proved"
Eg. If the accused is proved guilty, he will be punished.
Then A, C and D are good from a Tense perspective but as Sajjad mentioned D can be eliminated because drug cannot prove anything.
A is unnecessarily wordy, I would pick C (I don't see any problem with C unless GMAT discards "proved")

Why I picked B:

B uses "proven" - the past participle form which means "proven to cause" is a participial modifier modifying drug:
Any drug proven to cause Cancer will be denied approval.
same as
Any child found running in the classroom will be punished.

So B is grammatically correct plus concise. I am not sure how can we use "is proven" in a sentence. It is a past participle form so should come with has/have/had or has/have/had been
Can you please confirm if I am correct in this approach and clarify?

This question can easily be solved if you remember this rule:
prove(simple tense)
proved(past tense)
proven(passive)
And,Vpp is the only accepted form.
According to above, Option A&C are definitely wrong.
Option D is wrong because:
it changes the intended meaning to "drug proves sth. itself".
In option E:
"S+Ved" is actually wrong.
While "S+Vpp(passive)" corrects this error.

Posted from my mobile device

Thanks a lot Brian.
I guess I got mixed up with past and passive forms.

I was thinking of another passive sentence with an irregular verb:-
The movie seen more than a hundred times by her, is the one she wants to see again.

And I realized, in passive sentences, the verb always takes the third form - in the case of the question - "Proven". So, only B is correct.

Thanks again