What is the most significant $($most important$)$ difference between C and C$++?$ a$.$ C can understand $++$ code, but C$++$ cannot understand C code b$.$ C$++$ is object oreinted and allows for programmers to build abstractions C and C$++$ are both equally good at writing object oriented code in$,$ but C is better for other c$.$ stuff d$.$ C is older and can be trusted