Final answer:
The letter 'd' is a reflection over a vertical line of the letter 'b'. It is the only letter in the choices provided that becomes a mirror image of 'b' when reflected this way. Option C is the correct answer.
Step-by-step explanation:
The student's question involves identifying which letter would be the reflection of the letter 'b' over a vertical line. To answer this, think of how the letter 'b' would look if you flipped it directly over a line running up and down. The lowercase 'b' has a straight line with a loop or bubble on the right side.
When reflected over a vertical line:
The letter 'a' does not change in a way that makes it resemble a 'b'.
The letter 'f' is not a mirror image of 'b'.
The letter 'c' does not resemble 'b' when reflected.
The letter 'd' becomes a mirror image of 'b' when reflected over a vertical line.
Therefore, the correct answer is C) d.