5) D

We are looking for a person who uses 2 functions for the same time and 2 other functions for the same amount of time.

(The white section is equal to the black section. The light grey and semi-dark grey are equal in proportions too)

The darkest grey section is in lesser proportion than the light grey and semi-dark grey. So it cannot be Amos. She uses browser and social media for 30 mins but uses apps for 40 mins, which is more than browser and social media.

The darkest grey section is in higher proportion than the white and black sections. It cannot be Bryn as calls are in lower proportion (10 mins) than email and apps.

It cannot be Clive, as he does not use any two functions for the same amount of time.

Dolly: Email and social media can represent the black and white (two smallest equal sections), calls and apps can represent the light grey and semi-light grey (two largest equal sections) and browser can represent the darkest grey section.
It can be Dolly.

Eshan uses three functions for equal amounts of time. So the pie chart cannot represent Eshan.

So the answer is Dolly.