Consider the following Turing machine

$(A,a)(B,a,R)$

$(A,b)(B,b,R)$

$(B,a)(A,a,L)$

$(B,b)(A,b,L)$

$(B,$ Blank $)(C,$ Blank, $R)$

$C$ is the final state.

On input $\text{'}$ab$\text{'},$ the machine will?

Halt on accepting state

Go to infinite loop

crash

reach final state but will not halt