Answer:
The question lacks options, the options are:
A) All cells contain a nucleus.
B) All cells come from other living cells
C) All living organisms are made of one or more cells.
D) Cells are the basic unit of structure and function of all living things.
The answer is A
Explanation:
In 1830's, three scientists named; Mattias Schleiden, Theodor Schwann and Rudolph Virchow contributed to describing the basic properties of the cell, which they proposed in their so named CELL THEORY. This widely accepted cell theory has three components:
All living organisms are made up of one or more cells.
Cells are the basic and fundamental unit of life
All existing cells come from cells that have previously existed.
It was not proposed that all cells have a nucleus
