Which of the sentences below displays the correct punctuation?

(1 point)
Responses

The patient looked at the doctor as though he had never seen her before.
The patient looked at the doctor as though he had never seen her before.

Even though Laura is very young she is already a skilled chess player.
Even though Laura is very young she is already a skilled chess player.

Carlos asked me to buy the gift, since I know our friend’s tastes better than he does.

Carlos asked me to buy the gift since I know our friend’s tastes better than he does.