Answer:
D)groups 1 and 2
Explanation:
The s-block of elements are made up of those chemical elements we can find in groups 1 and 2 on the periodic table.
A periodic table of element is based on the periodic law which states that "the properties of elements are a periodic function of their atomic number".
In the table;
The s-block consists of elements in groups 1 and 2 having an outermost ""ns"" shell configuration. They are predominantly metals.
For Option A, groups 3-12 is the D-block
Option B, group 18 is filled with noble gases and it makes up the p-block
Option C, group 13-18 is makes up the p-block too.
So, the s-block is made up group 1 and 2 elements.