Which sentence uses punctuation correctly?

a. At times elephants show, extraordinary intelligence.

b. At times elephants show extraordinary intelligence.

c. At, times elephants show extraordinary intelligence.

d. At times, elephants show extraordinary intelligence.

Punctuations are much needed when we construct sentences. They greatly affect how the sentence will mean to the reader depending on where they are added. They divide words, sentences, and clauses to give more emphasis on the idea being voiced out. In the sentences above, only letter d which is "At times, elephants show extraordinary intelligence." makes sense. The idea of the sentence is that there moments that elephants exceed to their expected behaviors and actions which reflect their intelligence.