Answer:
Option C
Explanation:
Given planes are
2x+y+2z-8=0
and 2x+y+2z+$\frac{5}{2}$=0
Distance between two planes
= $\frac{|c_{1}-c_{2}|}{\sqrt{a^{2}+b^{2}+c^{2}}}=|\frac{-8-\frac{5}{2}}{\sqrt{2^{2}+1^{2}}+2^{2}}|$
= $\frac{\frac{21}{2}}{3}=\frac{7}{2}$
