Answer:
<em>The correct option is A) an increase in oxygen levels, which led to the extinction of many anaerobic organisms.</em>
Explanation:
Photosynthesis can be described as a process in which food (glucose) is produced by photosynthetic organisms by using carbon dioxide, water along with light energy from the sun. Oxygen is released as a by-product of this reaction. The process of photosynthesis initially allowed for oxygen gas to get accumulated in the air. This caused the rise of aerobic organisms who required oxygen for respiration. Before the photosynthesis organisms evolved, there was not enough oxygen gas on earth to support the life of aerobic organisms.
Photosynthesis and cellular respiration both somewhat involve each other.
Answer : Aluminum
Explanation : Symbols are the short forms which are used to define an element. The given element has the symbol as 
is Aluminum in +3 oxidation state and is a cation which can donate its 3 electrons to other species.
Therefore, the answer is Aluminum.
Answer:
These 2 might be the best answers:
A. Contain cells that connect to form pipes
C. Transport water and food
