单项选择题

A.-9dBm~-2.5dBm;-18dBm~-2.5dBm
B.-18dBm~-2.5dBm;-9dBm~-2.5dBm
C.-20dBm~-14dBm;-31dBm~-14dBm
D.-19dBm~-10dBm;-24dBm~-10dBm