To find the ideal temperature for baking muffins, a student plans an experiment to assess the taste and texture of muffins baked at different temperatures. The student pours 3 batches of muffins from the same batter into baking cups and assigns them to different oven temperatures: 350 degrees, 375 degrees, or 400 degrees. Each batch is baked for 10 minutes, and after appropriate cooling time, the muffins are assessed for taste and texture. What is the explanatory variable in this experiment?

the baking time
the 3 batches of muffins
the baking temperature
the taste and texture of the muffins