The following code illustrates which Python data structure?

$[(\text{'}$Study for Data Science Class', 'Respond to Discussion Thread', 'Week $1\text{'}),(\text{'}$Finish Lab $1\text{'},$ 'Start Lab $2\text{'},$ 'Week $2\text{'}),(\text{'}$Listen to Beethoven', 'Appassionata III', 'Week $3\text{'})]$

a$.$ list

b$.$ dictionary

c$.$ tuple

d$.$ set