Question

how is item a different from item b?
the crust under the ocean in item a is thicker than the crust under the mountain in item b.
the mantle under the ocean in item a is thinner than the mantle under the mountain in item b
the crust in item a is found partially below sea level as compared to the crust in item b.
the mantle in item a is located far below a mountain as compared to the mantle in item b.

Explanation:

Step1: Analyze each option

• Option 1: Oceanic crust is thinner than continental crust (mountain is on continental crust). So this option is wrong.
• Option 2: Mantle thickness is not indicated as different in the given way in the diagrams.
• Option 3: In Item A (Hawaii - oceanic area), part of the crust (the oceanic crust) is below sea level. In Item B (California - continental area with mountain), the crust is mostly above sea level. This option is correct.
• Option 4: Mantle is below both crusts (oceanic and continental) in a general sense as per the diagrams, no such difference as described.

Answer:

The crust in Item A is found partially below sea level as compared to the crust in Item B.