Answer:
Step-by-step explanation:
None of the other answers matter but the right answer which A. Silicon has an outer shell of 4. Carbon can connect with 4 elements because of its outer shell. CH4 is the simplest example. But C2H6 is also possible.
H H
H - C - C - H
H H
There are 4 connections to the outside world for the Carbon (C) on the left.
It has 3 hydrogens connected on to it and one of its connecting electrons goes with the other carbon on the right.
Silicon can do the same thing.