Which table shows exponential decay? a 2-column table has 4 rows. the first column is labeled x with entries 1, 2, 3, 4. the second column is labeled y with entries 16, 8, 4, 2. a 2-column table has 4 rows. the first column is labeled x with entries 1, 2, 3, 4. the second column is labeled y with entries 16, 128, 8, 4. a 2-column table has 4 rows. the first column is labeled x with entries 1, 2, 3, 4. the second column is labeled y with entries 16, 12, 9, 7. a 2-column table has 4 rows. the first column is labeled x with entries 1, 2, 3, 4. the second column is labeled y with entries 16, 8, 3, 1.