Based on the information provided in the text about Alex's thinking, he may identify as:
Transgender people.
People who consider themselves transgender, cover many options: from those who do not feel in accordance with the sex they were born, people who are attracted to people of both sexes, to people who do not feel attracted to any gender or not they are considered part of none.
The other options provided by the text are not valid since cisgender people feel according to the sex they were born, gender fluid people change gender on various occasions, and intersectionality is dedicated to corroborating the interrelation between sexuality and other social factors.
Therefore, since Alex feels no gender and prefers to use neutral pronouns, he can identify as a "transgender" person.
More information:
https://brainly.com/question/10441089?referrer=searchResults