The activities of our current leader have led to a signifcant increase

Major concepts tested:
• Subject/verb agreement
• Countable/uncountable nouns
• Led to/significant in increasing (active verbs)

Split #1: activities HAVE/has

The subject of the sentence is "activities."
The subject is not "leader."

The object of a preposition cannot be the subject of the sentence.*
"Leader" is the object of the preposition "OF."

The word "activities" is plural. It requires a plural verb.

Incorrect: activities ... HAS

(C) has led to
(D) has been significant
(E) has significantly increased

Eliminate C, D, and E

Split #2: ISSUES - countable or uncountable?

Issues are countable.
One issue, two issues, three issues ...

Correct: The CEO listed 10 issues on her agenda for the weekly meeting.

Correct: The CEO listed a number of issues on his agenda for the weekly meeting.

We use "a NUMBER OF" for countable nouns.

We use "an amount of" for uncountable things such as love, water, music, luggage, and rice.
One rice, two rices
Option B incorrectly uses amount of to modify issues:
... increase in the amount of issues

Eliminate B

By POE, Answer A is correct.

Check and rename parts that do not determine the answer (the last part of every option is the same)

The activities of person X have led to a significant increase in the number of issues relating to Y.

The subject and the verb agree. The number of issues is correct.

ANSWER A