Suppose for Some Base $b>0(b \neq 1)$ That $\log _{b} 2=A, \log _{b} 3=B, \log _{b} 5=C$

Multiple Choice

Suppose for some base $b>0(b \neq 1)$ that $\log _{b} 2=A, \log _{b} 3=B, \log _{b} 5=C$ , and $\log _{b} 7=D$ . Express the given logarithms in terms of A, B, C, or D.
- $\log _{b} 21$

A) $B+D$
B) $\mathrm{B}+\mathrm{C}$
C) $A+B$
D) $A+D$