Option doesn't solve everything. Sometimes overloaded functions provide a less confusing API.

options-or-overloads.scala

/* Function using Option */

object Hello {
  
  def to(name: Option[String] = None) =
    "Hello " + (name getOrElse "world")

}

println(Hello.to(null)) // Causes NullPointerException
println(Hello.to(Some(null))) // "Hello null"

/* Overloading functions but using an underlying Option prevents the possibility of NullPointerException */

object Hello {

  def to = 
    to(name = None)

  def to(name: String) =
    to(name = Option(name))

  private def to(name: Option[String]) =
    "Hello " + (name getOrElse "world")

}

println(Hello.to(null)) // "Hello world"
println(Hello.to(Some(null))) // Not possible