which of the following bit patters $($represented in hexadecimal notation$)$ represents a negative number in two's complement notation a$\mathrm{.}3$F b$.$A$6$ c$\mathrm{.}55$ d$\mathrm{.}7$E e$\mathrm{.}0$F f$\mathrm{.}00$ g$\mathrm{.}99$