Evaluate the following Assertion (A) and Reason (R) and choose the correct option.

Assertion (A): A particle moves along +x with v = v₀ - kx (k > 0 and v > 0). Its acceleration increases linearly with x.

Reason (R): Since a = v(dv/dx), we get a = (v₀ - kx)(-k) = k²x - kv₀, which is a linear function of x with positive slope k².