A combinational circuit has $2$ inputs $($a$,$ b$)$ and $2$ outputs $($f$1,$ f$2)$ and Its truth table is

a b f$1$ f$2$

$0010$

$0101$

$1001$

$1110$

Which expressions are true about f$2?$

Group of answer choices

f$2=$ a'bf$1+$ ab'f$1\text{'}$

f$2=$ a$\text{'}$b $+$ ab$\text{'}$

f$2=$ a$\text{'}$b$\text{'}+$ ab

f$2=$ a xor b

f$2=$ m$1+$ m$2$

none of above