100112 + *****2 + 111002 + 1012 = 10011112

Correct Answer: Option B

Explanation

Convert the binary to base 10 and they convert back to base two
10011₂ + xxxxx₂ + 11100₂ + 101₂ = 1001111₂
(1 × 2⁴ + 0 × 2³ + 1 × 2² + 1 × 2¹ + 1 × 2⁰) + xxxxx₂ +(1 × 2⁴ + 1 × 2³ + 1 × 2² + 0 × 2¹ + 0 × 2⁰) + (1 × 2² + 0 × 2¹ + 1 × 2⁰)
= (16 + 0 + 0 + 2 + 1) + xxxxx₂ + (16 + 8 + 4 + 0 + 0 ) + (4 + 0 + 1)
=(64 + 0 + 0 + 8 + 4 + 2 + 1)
19 + xxxxx₂ + 33 = 79
xxxxx₂ + 52 = 79
xxxxx₂ = 79 − 52
xxxxx₂ = 27₁₀
( begin{array}{c|c}
2 & 27 \
hline
2 & 13 text{ rem 1}\
2 & 6 text{ rem 1}\
2 & 3 text{ rem 0}\
2 & 1 text{ rem 1}\
& 0 text{ rem 1}\
end{array}uparrow )
27₁₀ = 11011₂
Therefore xxxxx₂ = 27₁₀ = 11011₂

There is an explanation video available below.