The correct options are
B Wave B has a lower pitch than wave A.
D Wave B is louder than wave A.
The pitch of a sound depends on its frequency. Higher the pitch, higher the frequency. Also, frequency is equal to the inverse of time period. So, if the time period of a wave is more, it means its frequency is less, and hence it also has a lower pitch. So, wave B has a lower pitch than wave A.
Loudness depends on the amplitude. Larger the amplitude, louder is the sound. So, wave B is louder than wave A.