Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
Answer is option D. All of these choices are correct.
<u>Explanation</u>:
SNP or single nucleotide polymorphism is a location that showcases the difference in individual alleles by one base pair. Mainly, a genetic difference that happens between different individuals.
It is the most common variation in genetics among people. Further, every SNP represents the difference in single DNA building block known as a nucleotide. Many SNPs do not affect the health of a person. It helps in predicting a response of a person to drugs.
