Riddle??
It would a person.
Four legs- when a baby
two legs- adult life
three legs- when an elderly walks with a cane and their feet
Hoped this helped.
~Bob Ross®

The opposing force created, the conflict within the story generally comes in four basic types: Conflict with the self, Conflict with others, Conflict with the environment and Conflict with the supernatural.
Answer: This is a " WORD-FOR-WORD PLAGIARISM".
Explanation: Word-for-word plagiarism is a type of plagiarism were someone copies another person's work word-for-word, without acknowledging the source it is been copied from.
The student has copied the original source word-for-word without acknowledging the source. The word been copied is "where variables are measured separately and then a mathematical model is chosen to portray the relationship among the variables". Which is the same in both version.
Though the student has used it in a different form to describe and define a different context from the main source. It is still plagiarism, because the student has copied it from the main source without acknowledgement
Roman Catholisism is your answer