A ray of light of intensity I is incident on a parallel glass slab at point A as shown in diagram. It undergoes partial reflection and refraction. At each reflection, $25 \%$ of incident energy is reflected. The rays AB and $\mathrm { A } ^ { \prime } \mathrm { B } ^ { \prime }$ undergo interference. The ratio of $\mathrm { I } _ { \text {max } }$ and $\mathrm { I } _ { \text {min } }$ is :\\
(1) $49 : 1$\\
(2) $7 : 1$\\
(3) $4 : 1$\\
(4) $8 : 1$