If you want to join the science club; you may sign up in room 318. choose the answer that is the most effective substitute for the underlined part of the sentence. if no substitute is necessary, choose ‘leave as is.’ a) leave as is. b) join the science club, you may sign up c) join the science club: you may sign up d) join the science club you may sign up

The answer is indeed letter B)  join the Science Club, you may sign up

Explanation:

The original sentence has a punctuation problem. We have two clauses forming a conditional sentence. The first clause is the one that establishes the condition, the one that starts with "if". When the "if" clause comes first, it must be separated from the one that indicates consequence with a comma. Thus, the correct option is letter B, and the revised sentence would be:

If you want to join the Science Club, you may sign up in Room 318.

Note that when we start with the consequence, there is no need for a comma at all:

You may sign up in Room 318 if you want to join the Science Club.

i believe the answer is d