I lost 1k points pls help

Which of the following statements is true? a. poll data show that a majority of americans accept gay and b. open discussions of sexuality are welcomed by all families, c. homophobic stereotypes rarely occur in the media anymore. lesbian relationships. religious grougs, and social networks. d. poll data show that bisexuality and homosexuality are viewed positively by all parts of society

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine. what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.

If you know answer will mark brainliest