Step 1:
Public debt management refers to planning, raising, and handling government borrowings efficiently.
Step 2:
The primary aim is to obtain necessary funds at minimum possible cost and acceptable risk.
Step 3:
• Option (1) directly defines public debt management
• Other options represent partial activities only
Step 4:
Therefore, public debt management aims at:
\[
\boxed{\text{Raising required funding at desired risk and cost levels}}
\]
Hence, the correct answer is:
\[
\boxed{\text{(1)}}
\]