Answer:
- C. infinitely many solutions
Explanation:
We can tell that an equation has multiple/ infinitely many solutions if we try to solve it and get a variable or a number equal to itself.
Let's solve the given equation and see what we'll get :-

Add 10b to both sides:-

Simplify:-

Subtract:-


As we can see, both sides ended up equal, therefore, this equation has infinitely many solutions!
______________________
Hope this helps!
Have a great day!