Suppose I have a multiple choice question with five possible responses: A, B, C, D, E, and let's say no one picks A or E. How can I nevertheless force these on the x-axis, albeit at zero?

here are three things I've tried:

```
# generate data
response <- tibble::tibble(answer = sample(LETTERS[2:4], 20, replace = T))
p <- ggplot(response) + geom_histogram(aes(x = answer), stat = "count", breaks = LETTERS[1:5])
p # this doesn't work; still only B,C,D shown
# Turning into a factor doesn't help
response %>%
mutate(answer = factor(answer, levels = LETTERS[1:5])) %>%
ggplot() + geom_histogram(aes(x = answer), stat = "count", bins = LETTERS[1:5])
# another attempt w scale_x_discrete; nope
p + scale_x_discrete(breaks = c("A", "B", "C", "D"))
```

Any advice from the hive is much appreciated-