Given,
first term a₁ = k
General term;
a_{n} = 2a_{n-1}
Hence, third term (n = 3);
a_{3} = 2 a_{3-1} = 2a_{2} = 2 * (2a_{2-1}) = 4a_{1} = 4k
Hence, the answer is B: 4k.
