Write the structure of ethylene

Ethylene is $\mathrm{C_2H_4}$, with structure: $\mathrm{H_2C=CH_2}$

Count the bonds present

• There are 4 C–H single bonds.
• There is 1 C=C double bond between the two carbon atoms.

Recall bond composition

• A single bond contains 1 $\sigma$ bond.
• A double bond contains 1 $\sigma$ bond + 1 $\pi$ bond.

Calculate total $\sigma$ bonds

• From 4 C–H bonds: $4\sigma$
• From 1 C=C double bond: $1\sigma$

Total: $4 + 1 = 5\sigma$

Calculate total $\pi$ bonds

• From 1 C=C double bond: $1\pi$

Total: $1\pi$

Match with options

Therefore, ethylene has: $5\sigma \text{ bonds and } 1\pi \text{ bond}$

So the correct option is B.