When the hilum, chalaza and micropyle of ovule lie in the same long axis, it is known as :

The correct option is B Orthotropous
Orthotropous ovule is the simplest and primitive type of ovule in which micropyle, chalaza and funiculus lie in one vertical plane. Hence when the hilum, chalaza and micropyle of the ovule lie in the same longitudinal axis, it is known as orthotropous ovule.

Anatropous ovule is rotated by 180° and micropyle comes near to the funiculus. Chalaza and micropyle are in straight line but hilum is 90° to micropyle.

Amphitropous ovule, the body of ovule becomes curved and looks like the anatropous ovule but embryo sac also curves and becomes horse-shoe shaped.

Campylotropous ovule, the curvature is such that the micropyle comes to lie near the funiculus.

So, the correct answer is "option A"