Select the correct mirror image of the given figure when the mirror is placed at MN as shown.

Correct — B. Rule: MN is vertical, so the picture is reversed left to right and nothing changes height.

Read the given panel by its landmarks. The solid black block is top-left. The circle with its short tail is upper-right, the tail running up towards the top-right corner. The cube sits bottom-left, the small upright rectangle bottom-right, and a long narrow triangle has its sharp point on the left.

Now flip each landmark across a vertical line. The black block moves to the top-right, the circle to the upper-left with its tail now running up-left, the cube to the bottom-right, the rectangle to the bottom-left, and the triangle points right.

Option (b) is the panel that shows all five of those at once.

Why the others are wrong

• (a)
  The narrow triangle still points left, exactly as in the question, and a vertical mirror reverses every left-pointing form. The cube has also risen to the top while the circle has stayed on the right.
• (c)
  The black block has dropped to the bottom-left. A mirror at a vertical MN moves things sideways and never up or down, so the block has to stay at the top.
• (d)
  The black block is still on the left, dropped into the bottom-left corner instead of crossing to the right. The small upright rectangle has also changed height — bottom-right in the question, top-right here — and a vertical mirror never moves anything up or down.

A mirror on a vertical line MN produces lateral inversion. Left and right swap, top and bottom do not, and every slanting line keeps its height while reversing its direction.

The reliable method is landmarks, not whole pictures. Pick three or four features whose left-right position is unambiguous — a solid block, a circle with a tail, a pointed triangle — and check them one at a time.

The first landmark sitting at the wrong height eliminates an option immediately, because height is the one thing a vertical mirror never touches.

Key facts

• A mirror on a vertical line swaps left and right and leaves top and bottom unchanged.
• The black block is top-left in the given figure, so in the mirror it must be top-right.
• The narrow triangle points left in the given figure, so in the mirror it points right.

Common traps

• Choosing a panel that has flipped top and bottom as well, which is a rotation and not a reflection
• Comparing the overall shape instead of checking one landmark at a time

No directly related past PYQ was found.