An object of 4.2 cm height, stands on the main axis in front of a concave mirror and gives a virtual image of 8.8 cm height at an image distance with absolute value 18. cm. What is the radius of curvature of the mirror? Select the correct answer from the following list:

a) -7.27 cm

b) 4.44 dm

c) 32.9 cm

d) 14.4 dm