Sexual orientation was grounds for excluding immigrants from the united states until:

This was a non-protected status until 1990. Orientation was thought of as being a net negative to the nation and, thereby, grounds for exclusion because of the (unfounded) possibility of transmission of disease. In addition, orientation was used as a moral justification against inclusion due to the argument that LGB individuals would bring decline to the overall state of the country.

The correct answer is d. 1990.

Before the 90s, immigrants would sometimes be denied entry into the country because of their sexual preference and orientation. This was especially happening during the conservative periods when people didn't even know how HIV is transmitted and attacked people who were different.