Ktor CSS DSL

How does the correct declaration of the respondCss function look like?

1)

suspend inline fun ApplicationCall.respondCss(builder: CssBuilder.() -> Unit) {
    this.respondText(CssBuilder().apply(builder).toString())
}

2)

suspend inline fun ApplicationCall.respondCss(builder: CssBuilder.() -> Unit) {
    this.respondText(CssBuilder().apply(builder).toString(), ContentType.Text.CSS)
}

3)

suspend inline fun ApplicationCall.respondCss(builder: CssBuilder.() -> Unit) {
    this.respondText(CssBuilder().apply(builder).toString(), "CSS")
}

4)

suspend inline fun ApplicationCall.respondCss(builder: CssBuilder.() -> Unit) {
    this.respondText(CssBuilder().apply(builder).toString(), "text/css")
}

5)

suspend inline fun ApplicationCall.respondCss(builder: CssBuilder.() -> Unit) {
    this.respondText(CssBuilder().apply(builder).toString(), "Content-Type: text/css")
}