The decimal equivalent of the given binary number:
$(10111)_2=(23)_{10}$
$(1110)_2=(14)_{10}$
now we simply multiply these numbers in base $10$ radix.
$(23)_{10} \times(14)_{10}=(322)_{10}$
Now convert this decimal numbers to hexadecimal,
$(10111)_2\times (1110)_2=(142)_H$
Option $(C)$ is correct.