Which of the Factors Below Weaken the Hypothesis of Abiotic

Which of the factors below weaken the hypothesis of abiotic synthesis of organic monomers in early Earth's atmosphere?
1) the relatively short time between intense meteor bombardment and appearance of the first life forms
2) the lack of experimental evidence that organic monomers can form by abiotic synthesis
3) uncertainty about which gases comprised early Earth's atmosphere

A) 1
B) 2
C) 3
D) 1 and 3
E) 2 and 3