Answer:
Option A.
Explanation:
Option A directly tests the cause and effect. Option B simply argues it argumentatively without any solid evidence to show cause and effect. Option C only shows correlation and Option D only shows correlation as well.
Explanation:
HCL you can do it yourself .try again
Answer: 
Explanation:
A single displacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

Synthesis reaction is defined as the reaction where substances combine in their elemental state to form a single compound.
Decomposition reaction is defined as the reaction where a single substance breaks down into two or more simpler substances.

Combustion is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.
