And C, Why is it still in use, Aren't there alternatives?

No, there are not always alternatives.

Sometimes the alternatives are worse than C. C at some degree is portable, so some code can be reused. C is ideal for the microcontrollers which have limited memory. Think about having 1k of Ram and 4k of flash memory.Since at the assembly level each family of microcontrollers is different is very hard to learn each month another set of instructions ,and here comes C.Linux kernel is written in C too. C is just a tool , and once you get used to it is fine.

C is still in use because it is still the best tool for many jobs.

It is the only language available on every platform.

For many platforms, it is the only non-assembly language available at all - most microcontroller architectures, for example.