A function my_func() returns True when it executes normally.

The function my_func() returns True when it executes normally. To test this function using Python's unittest framework, the correct assertion to use is assertTrue. This method tests if the given expression evaluates to True.

Option A (self.assertTrue(my_func())): This assertion checks if my_func() returns True.

Option B (self.assertRaises(my_func())): This is used to check if a specific exception is raised, which is not applicable here.

Option C (self.assertEqual(my_func(), 'true')): This checks if my_func() returns the string 'true', which is not correct as my_func() returns a boolean True.

Option D (self.assertFalse(my_func())): This checks if my_func() returns False, which is the opposite of what is needed.