Respuesta :

One rule of logs is when you add logs, u can combine the parentheses​ by multiplying so..

log(10a) + log(100a)
log(10a × 100a). now multiply
log(1000a^2)

hope this helps C:
log(10a) + log(100a) 
log(10a × 100a). now multiply
log(1000a^2)

hope this helps!
Answer is C