Final answer:
The expression 105 x 10^4 simplifies to 1,050,000, which in proper scientific notation is written as 1.05 x 10^6, not matching any of the given choices.
Step-by-step explanation:
To simplify the expression 105 x 10^4, you move the decimal point in 105 four places to the right (as indicated by the exponent on 10), getting 1,050,000. However, to express this in proper scientific notation, you want one non-zero digit to the left of the decimal point. So, the number 1,050,000 is written as 1.05 x 10^6 in scientific notation, which matches none of the choices provided in the question.