Answer:
a. a disease
Explanation:
Pathogens are disease-causing organisms. For example, some bacteria and viruses are pathogens for different species.
Therefore, a tree with pathogens present is likely to have a disease. Different pathogens affect different trees. Examples include Anthracnose
, which is caused by a fungus
Warm air rises and eventually cools. Answer choice D.
The right option is; a. It is rich in minerals from volcanic deposits.
Volcanic soil (andisol) is a light and fluffy soil that is formed from volcanic ash and cinder deposits. Volcanic soil is very fertile because it is highly composed of non-crystalline minerals, such as allophane and imogolite from volcanic deposits. These minerals create strong bonds with organic matter which leads to the accumulation of organic matter in the soil. Volcanic soil has high water retention capability and it supports the growth of crops such as rice, maize and fruits.