PLEASE HELP!!!! I will give brainliest to whoever answers.

Answer:
Option #4 (3x)(4x+5)
Step-by-step explanation:
To find area of a rectangle, you have to multiply the length by the width. In this case, to find the width, you have to add 4x and 5, so 4x+5 become your new width value to multiply by 3x.