The engaging diameter in the following presentation is?

Ans. C. Mento verticalVarious diameter:a. Sub-occipitobregmatic diameter: Measured from below the occipital protuberance and the centre of the bregma or anterior fontanelleb. Sub-occipitofrontal diameter: Measured from below the occipital protuberance and the centre of the frontal suturec. Occipitofrontal diameter: Measure from the occipital protuberance to the glabella or root of the nosed. Mento vertical diameter: Measured from the point of the chin to the highest point of the vertexe. Sub-mento vertical diameter: measured from the point where the chin joints the neck to the highest point of the vertexf. Sub-mento bregmatic diameter: measured from the point where the chin joints the neck to the centre of the bregmag. Biparietal diameter: The diameter between the two parietal eminencesh. Bitemporal diameter: The diameter between the furthest points of the coronal sutures at the temples