Asecondary immune response differs from the primary immune response in that:
a. it is more rapid than the primary response and results in higher antibody levels.
b. it is slower than the primary response and doesn’t change the antibody levels.
c. it occurs at the same time as the primary response but results in a decrease in antibodies.
d. it only occurs in hyperallergic reactions and results in a decrease of antibodies.

Option A,  it is more rapid than the primary response and results in higher antibody levels.

Explanation:

When an antigen contacts the immunity system for the first time  it leads to a primary immune response. Since it is the first interaction, it requires more time   to produce effect.

While a secondary response occurs when the same antigen attacks the same person second , third or n number of times. During secondary response, the body already has a memory of primary immune response and thus it is faster.

Hence, option A is correct

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.

well the answer is 2!