Given the polynomial:

You need to remember the following definitions:
- The degree of a polynomial is the highest exponent.
- The Leading Coefficient is the number that multiplies the variable with the highest exponent.
- The Standard Form of a polynomial shows the terms in descending numerical order.
In this case, you can identify that:
1. The highest exponent of the polynomial is 5. Therefore:

2. The Constant Term is:

Therefore, you can rewrite it in descending numerical order:

Now you can identify that the Leading Coefficient is:

Hence, the answer is: Last option.