Which One of the Following Mathematical Expressions Is Correct for Constructive

Multiple Choice

Which one of the following mathematical expressions is correct for constructive interference for two beams of light in the double slit experiment?

A) Path Difference = (m - 1/2) λ, m = 0, ±1, ±2, . . .
B) Path Difference = λ/m, m = 0, ±1, ±2, . . .
C) Path Difference = mλ, m = 0, ±1, ±2, . . .
D) Path Difference = m , m = 0, ±1, ±2, . . .
E) Path Difference = m/λ, m = 0, ±1, ±2,. . . .