Indicate the hydrocarbon in which the mass fraction of carbon is equal to the mass fraction

Indicate the hydrocarbon in which the mass fraction of carbon is equal to the mass fraction of carbon in benzene 1) C6H14 2) C4H6 3) C2H2 4) CH4

1) Mr (C6H6) = 78;
2) ω (C in C6H6) = N (C in C6H6) * Ar (C) * 100% / Mr (C6H6) = 6 * 12 * 100% / 78 = 92.31%;
3) Mr (C6H14) = 86;
4) ω (C in C6H14) = N (C in C6H14) * Ar (C) * 100% / Mr (C6H14) = 6 * 12 * 100% / 86 = 83.72%;
5) Mr (C4H6) = 54;
6) ω (C in C4H6) = N (C in C4H6) * Ar (C) * 100% / Mr (C4H6) = 4 * 12 * 100% / 54 = 88.89%;
7) Mr (C2H2) = 26;
8) ω (C in C2H2) = N (C in C2H2) * Ar (C) * 100% / Mr (C2H2) = 2 * 12 * 100% / 26 = 92.31%;
9) Mr (CH4) = 16;
10) ω (C in CH4) = N (C in CH4) * Ar (C) * 100% / Mr (CH4) = 1 * 12 * 100% / 16 = 75%;

Option 3).