Which of the following will call a function named setBlue() when a text box with id = "blue" gets the focus?

a.
```
onfocus = "blue" onclick = ("setBlue()");
```

b.
```
onfocus.blue = setBlue()
```


c.
```
id = "blue" onclick = setBlue()
```

d.
```
onfocus = "setBlue('blue')"
```

d.
```
onfocus = "setBlue('blue')"
```