From what is known about spring tides and neap tides, you can conclude that

a). the sun’s gravity exerts the most power when the moon is on the opposite side of the earth from the sun.
b). the height of high tides varies with the phases of the moon.
c). spring tides and neap tides affect the phases of the moon.
d). the moon revolves around the earth every 14 days.

The answer is B

Centration is the correct answer

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.