已知由正数组成的等比数列｛a_n｝中,公比q="2," a₁·a₂·a₃·…·a₃₀=2⁴⁵, 则
a₁·a₄·a₇·…·a₂₈= (      )

A．2^5

B．2^10

C．2^15

D．2^20