The measurement indicated by the line across the center of the cell is best referred to as:. a. Area
b. Volume
c. Diameter
d. Radius

I'm guessing, but if the image is a circle, and the line touches both sides it's the diameter. If the line is only half of the circle then, it's a radius.

Explanation:

Volume is L x W x H (Length x Width x Height)

Area is L x W (Length x Width)

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.

oxygen +1 most likely