.HELP ME PLEASEE IM IN AN EXA Billy was asked to solve 3^5∙3^4. He got 9^20. What error did he make? *

a) When he multiplies exponents, he is supposed to add the base and the exponent
b) When he multiplies exponents, he is supposed to multiply the base and keep the exponents
c) When he multiplies exponents, he is supposed to keep the base and add the exponents if the base is the same
d) None of the above