What is 105,000 written as a scientiffic notation?

When you wish to rotate numbers to find their exact scientific notation you must take in consideration if the problem is that of sum or subtraction ( this means that you always look for the least sifers posible)the answer to this is  1x10^5

A polynomial is defined as a collection of variables and constant terms combined by various mathematical operations. The exponents of the variables in a polynomials must be non-negative integers.

If you observe the given options, one of the option (option B) contains a negative exponent. Hence the expression in option B is not a polynomial.