Circumference and diameter

Which of these graphs could be the graph showing the circumference of a circle in terms of its diameter ?
Age
11 to 14
Challenge level
filled star empty star empty star
Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving
Being curious Being resourceful Being resilient Being collaborative

Problem

Which of the following could be the graph showing the circumference C of a circle in terms of its diameter d?

Circumference and Diameter



If you liked this question, here is an NRICH task which challenges you to use similar mathematical ideas.