The figure shows the letter m and four of its transformed images—a, b, c, and d: a coordinate plane is shown. a figure m has endpoints at 3 comma 1, 3 comma 3, 5 comma 1 and 5 comma 3. figure a is shown with endpoints at negative 2 comma 1, negative 2 comma 3, negative 4 comma 1 and negative 4 comma 3. figure b has endpoints at negative 2 comma negative 1, negative 2 comma negative 3, negative 4 comma negative 1 and negative 4 comma negative 3. figure c has endpoints at 0 comma negative 1, 0 comma negative 3, 2 comma negative 1 and 2 comma negative 3. figure d has endpoints at 3 comma negative 1, 5 comma negative 1, 3 comma negative 3 and 5 comma negative 3. which of the four images was formed by a reflection of the letter m? a b c d