Julius, a manager in a data analytics company, has assigned five of his team members to a particular project. At the end of every week, he is required to submit a progress report to his supervisor. For this, he needs to create a chart that will allow him to efficiently track his team members' progress by scheduling different activities and plotting the planned and actual hours put into those tasks. In this case, which of the following charts would best fulfill Julius's requirement?

a$.$ The Gantt chart

b$.$ An area chart

c$.$ A flowchart

d$.$ The Pournelle chart