Consider that the Transmission Error Count $($TEC$)$ of ECU A is $120$ when it comes under a bus$-$off attack by another ECU B$.$ At the beginning of the bus$-$off attack, the TEC of ECU B is $112.$ How many $($re$-)$transmissions of the targeted message by the victim ECU A will take it to bus$-$off mode?

$16$

b $20$

c $21$

d$.22$