I have a data frame (data.frame) that looks like this (simplified):

```
[1] [2] [3]
[A] 2 4 3
[B] 1 5 7
[C] 2 3 4
```

I want to subset out all the columns that correspond to row A >= 3. So that if I did that the resulting matrix would look like this:

```
[2] [3]
[A] 4 3
[B] 5 7
[C] 3 4
```

I can't get this for the life of me. I tried:

```
Test <- data.frame[, data.frame$"A" >= 3]
```

And I get returned 3x0