The correct answer is A. My cat likes sleeping in the window and my dog likes sleeping on me.
Explanation:
In writing, the punctuation refers to the use of comma (,), period (.), semicolon (;), colon (:) and others used to separate different element withing a sentence according to strict grammar rules. In the case of the sentence "My cat likes sleeping in the window and my dog likes sleeping on me" this is a compound sentence that integrates two main ideas, the first one is "My cat likes sleeping in the window" and the second one is "my dog likes sleeping on me" and in this case besides using the conjunction "and" to separate both a punctuation mark and more specifically a comma is required as "My cat likes sleeping in the window, and my dog likes sleeping on me". On the other hand, other sentences presented are simples sentences and do not require any punctuation. Therefore it is the first sentence the one that is missing a punctuation mark.
