Which graph represents the relationship between the intensity of incident light on a metal plate and the resulting photoelectric current?

In the photoelectric effect,the photocurrent:

For most metals, threshold frequencies lie in which region?

$A$ photocell is receiving light from a source placed at a distance of $1 \ m$. If the same source is placed at a distance of $2 \ m$,then the ejected electrons:

Describe Hallwach's and Lenard's observations regarding the photoelectric effect in short.

Assertion : Kinetic energy of photoelectrons emitted by a photosensitive surface depends upon the intensity of incident photon.
Reason : The ejection of electrons from a metallic surface is possible with a frequency of incident photon below the threshold frequency.