The answer is oxidation or chemical weathering. There are three main types of weathering, which includes, mechanical weathering, biological and chemical weathering. Mechanical weathering is caused by wind, sand rain, thawing, freezing, and other forces that can physically alter the rock. Biological weathering is caused by the activities of plants and animals as they grow, nests and burrow. Chemical weathering is caused by chemical reactions rather than by mechanical means.
The correct answer is option B. The scientists were studying if the mud snails can reproduce both sexually and asexually. The characteristics in the study included parameters such as the mating season, number of offspring, effect of environmental stress conditions and lack of mates. Out of all the parameters being studied can affect asexual reproduction in the mud snail but lack or presence of mates is a parameter required to be studied to determine the mode of reproduction i.e. sexual or asexual because need for mates or mate dependent reproduction occurs in case of sexual reproduction.
Usually blood transports nutrients