Final answer:
The number 9.3 x 10^3 in standard form is 9,300. The decimal point is moved three places to the right, converting the scientific notation to standard form.
Step-by-step explanation:
The number 9.3 x 10^3 written in standard form is 9,300. To convert a number in scientific notation to standard form, you move the decimal point to the right for positive exponents of ten. In this case, you move the decimal point 3 places to the right (because of the exponent 3), which gives you 9300.
Therefore, the correct answer is: a. 9,300.