Question

two planes intersect in exactly ____.
one point
one line
one plane
two lines

Explanation:

In geometry (a subfield of Mathematics), the intersection of two planes is a fundamental concept. By the postulates of plane geometry, when two planes intersect, they do so in a straight line (a one - dimensional figure). A single point would be the intersection of two lines (not planes), a single plane would imply the two planes are coincident (not intersecting in the sense of distinct planes), and two lines as an intersection of two planes is not in line with geometric principles. So the correct answer is "one line".

Answer:

one line