ndirect manipulation results from(a) Operations being difficult to con-ceptualize in the graphical system(b) Graphics capability of the systemis not limited(c) Difficulties for people to learnand remember all the necessaryoperations and actions(d) None of the above

Indirect manipulation typically results from both (a) Operations being difficult to conceptualize in the graphical system and (c) Difficulties for people to learn and remember all the necessary operations and actions.

(a) If the operations are complex or abstract, it can be challenging to represent them graphically in a way that users can easily understand and manipulate.

(c) Similarly, if there are too many operations or actions required, it can be overwhelming for users to learn and remember them all, leading to indirect manipulation.

Therefore, the answer is not (b) Graphics capability of the system is not limited, as having unlimited graphics capability would generally support direct manipulation by allowing more intuitive and flexible user interfaces.

Also, the answer is not (d) None of the above, since both (a) and (c) are valid reasons for indirect manipulation.