(A) greatly benefit brain function

(B) and help avoid the negative

(C) short afternoon naps can

(D) effects of prolonged sleep sessions

The following question gives a sentence which has been divided into four parts which may not be in their correct order of narrative. The sentence is then followed by five options, one of which gives the sequence of the rearranged parts to make the sentence meaningful. Choose the option which gives the correct sequence of the parts. If the sentence is already arranged in the correct sequence, mark option " No rearrangement required " as the answer.

The correct option is CABD.

Let's analyze the given parts step-by-step to form a grammatically correct and meaningful sentence:

Step 1: Identify the Subject/Topic
Part (C) "short afternoon naps can" introduces the main subject of the sentence, which is "short afternoon naps", followed by the modal verb "can". Therefore, the sentence should begin with part (C).

Step 2: Find the main verb phrase
The modal verb "can" requires a main verb in its base form. Part (A) begins with the verb "greatly benefit", which correctly completes the modal verb phrase: "short afternoon naps can greatly benefit brain function". Thus, part (A) directly follows part (C).

Step 3: Connect with additional information
Part (B) starts with the conjunction "and help avoid the negative", which adds a second benefit of napping: "and help avoid the negative...". This logically connects with part (A).

Step 4: Complete the object of the verb
Part (D) "effects of prolonged sleep sessions" finishes the thought introduced in part (B) ("negative effects of prolonged sleep sessions").

Combining the parts in the sequence C -> A -> B -> D gives:

"Short afternoon naps can greatly benefit brain function and help avoid the negative effects of prolonged sleep sessions."

This forms a complete, coherent, and grammatically sound sentence. Therefore, CABD is the correct sequence.