When the customer says: "The PA is only for speech reinforcement!", which of the following...

Subwoofers are generally not required for a PA system focused solely on speech reinforcement because they reproduce low-frequency sounds that are not necessary for intelligibility of spoken word. Speech reinforcement systems typically prioritize clarity in the mid and high frequencies.

CTS Technology Specialist Reference

The CTS curriculum states that speech reinforcement systems should prioritize mid and high frequencies, which are critical for voice clarity, while subwoofers are typically used in music reinforcement for low-frequency response.