The problem does not ask you to calculate strains - 6.4 A asks you to compare the magnitude of normal stress at a, b and c. 6.4B asks you to calculate A* and y*.

Remember that the location of the centroid, and thus the neutral axis, is affected by where the most mass is concentrated. This cross-section has a higher concentration of mass near the top, so the centroid would be shifted upwards.

How do we find out where the maximum strain is? We are not fully given each dimension.

The problem does not ask you to calculate strains - 6.4 A asks you to compare the magnitude of normal stress at a, b and c. 6.4B asks you to calculate A* and y*.

Which is the neutral axis/ bending plane? Is it at B for the T shape and and the XZ plane for the block?

Remember that the location of the centroid, and thus the neutral axis, is affected by where the most mass is concentrated. This cross-section has a higher concentration of mass near the top, so the centroid would be shifted upwards.