Select the correct combination of mathematical signs to replace the * signs and to balance the given equation.
21*5*61*84*4*8*15

A

$$−,\div,+,−,=,\times$$

B

$$\times,−,=,\div,+,+$$

C

$$+,−,=,\times,−,\div$$

D

$$+,\times,−,=,+,−$$