Given below are four statements (i-iv) each with one or two blanks. Select the option which correctly fills up the blanks in two out of four statements.

i. Wings of butterfly and birds look alike and are the results of __A__, evolution.

ii. Miller showed that CH 4 , H 2 , NH 3 and ___A____, when exposed to electric discharge in a flask resulted in formation of __B__.

iii. Vermiform appendix is a __A__ organ and an __B__ evidence of evolution.

iv. According to Darwin, evolution took place due to __A__ and __B__ of the fittest.