This series operates in triplets where the third number is the product of the first two divided by the second number of the previous triplet. 5×20÷8≈12.5, then 24×6÷12=12, so 2×8÷12≈1.33, but the pattern is actually: each triplet (a,b,c) follows c = a×b÷(previous triplet's second element). Looking simpler: 5×4=20, 20+4=24, 24÷4=6, 6÷3=2, 2×4=8, 8+4=12, 12÷4=3. The answer is 3. Option B is correct.