Choice "B" is correct. Since control risk is assessed at a low level, tests of controls would be required to evaluate the effectiveness of the internal controls to support that assessed level. However, the need for some substantive tests of transactions is never eliminated.
Choice "d" is incorrect. Extensive tests of property and equipment balances would not typically be required when control risk is assessed at a low level.
Choice "c" is incorrect. Since control risk is to be assessed at a low level, tests of controls would be required. Analytical procedures would not be particularly useful, since property and equipment transactions are subject to management discretion.
Choice "a" is incorrect. Analytical procedures would not be particularly useful, since property and equipment transactions are subject to management discretion. Year-end balances may therefore be unpredictable.