Final answer:
Implementing strategies such as offering choices, using real-world applications, and creating challenging tasks in a high school setting is expected to primarily increase student motivation.
Step-by-step explanation:
A high school teacher can expect implementation of strategies such as offering student choices, incorporating real-world applications, and designing appropriately challenging tasks to primarily increase student motivation. These strategies are known to enhance student engagement and interest in the learning process, making them feel more connected to the material. By providing choices, students feel a sense of autonomy; real-world applications make learning more relevant; and appropriately challenging tasks ensure students are neither bored nor overwhelmed, thereby promoting sustained motivation.