Answer: [A] addition property of equality
Step-by-step explanation:
  Mitch used the addition property of equality because he added 43 to both sides of the equation.
     75r - 43 = 332
     43 + (75r - 43) = (332) + 43
     75r = 375
     Learn more about some different properties used when solving equations here:
     https://brainly.com/question/26092220