Given two planes P1: x+2y+2z=0 and P2: x+2z=5, which of the following options explains why these two planes intersect?

a. The planes have the same slope and intercept.
b. The planes have parallel lines.
c. The planes have perpendicular lines.
d. The planes have intersecting lines.
Find the cosine of the acute angle between two planes.
Find the symmetric form of the equation of the line.
(Note: Removed unnecessary space and unnecessary words)