Final answer:
Option (C) 5.34 x 10^3 is expressed in engineering notation.
Step-by-step explanation:
The expression that is expressed in engineering notation is option (C) 5.34 x 103.
Engineering notation, also known as scientific notation, is a way of representing numbers that are either very large or very small. It consists of a number between 1 and 10 multiplied by a power of 10. In option (C), 5.34 is multiplied by 10 raised to the power of 3, which represents 3 decimal places shifted to the right.