In the following question, two columns are given, containing three phrases each. A phrase from the first column may or may not connect with a phrase from the second column to make a grammatically and contextually correct sentence. There are four options, three of which display the sequence(s) in which the phrases can be joined to form a correct sentence. If none of the phrases make a correct sentence, mark ‘None of these’ as your answer. 

Column 1	Column 2
A. The puzzle of what kind of phenomenon life is	D. has pursued us throughout history.
B. One core observation though is that individual living things	E. and collectives of living things tend to be self-stabilizing.
C. There doesn’t seem to be any guarantee	F. that life will always make a planet more suitable for life.