Tissues and organ systems.
here is the full chart:
cell --> tissue --> organ --> organ system --> organism
(think: group of [insert former here])
e.g. tissue=group of same cells
(et.al)
The whale still has traces of a hip and pelvis bones in the back of his body witch scientist think they used to walk on land
An allele is a variation of a gene the assumption here that by particular character you also mean gene
Answer:
Option B, 
Explanation:
Given-
The average surface area of one foot pad of an elephant is

Weight of an Asian elephant is
newton
As we know, pressure is equal to total weight divided by total area of the surface on which it is concentrated.
Thus, pressure on one foot pad of elephant is 

Hence, option B is correct answer