Answer: A) forward chaining
Step-by-step explanation:
Forwards chaining is the process in which facts are analyzed to be known and then planning to gain certain rules and condition to perform task.This process moves step by step in forward manner to achieve solution.
According to the question,Doug's mom is using forwards chaining as she is collecting components of making bed through analysis and then teaching steps involved in them one by one in subsequent order.
Other options are incorrect because trial task presentation, backward chaining and graduated guidance are not the method used by Doug's mom.Thus, the correct option is option(A).