For what value of k, x² - kx + 3 will be exactly divisible by x - 1?

None of these

If x - 1 is a factor of x² - kx + 3, then substituting x = 1 should make the expression zero.

Substituting x = 1 in x² - kx + 3 = 0 gives:

(1)² - k(1) + 3 = 0 ⟹ 1 - k + 3 = 0 ⟹ k = 4.