omosexuality is seen only in humans. has been documented for only a few hundred years in only a few societies. likely reflects the input of a number of genes and environmental factors. is inherited from a mutation on the X chromosome. is only the result of environmental influences.

Homosexuality likely reflects the input of a number of genes and environmental factors

Explanation:

Sexual orientation can be defined as the attraction that experiments an individual self-identified with a particular gender (either male or female) to other persons according to their sex, this orientation may be classified into three categories: heterosexual (attraction for people of opposite sex), homosexual (same-sex) and bisexual (either sex). In the last years, the mechanisms involved in sexual orientation have been subject to intense research. In this regard, the main part of the scientific community agrees that sexual orientation is the result of the complex interaction between genetic and environmental factors. This hypothesis is supported by the fact that genes whose expression is associated with particular human behaviors, including sexual orientation, have been recently identified and mapped. Moreover, it has been shown that environmental factors such as, for example, hormone exposure before birth (i.e., during fetal programming) may also determine sexual orientation.

one would be wind another would be water density