Concept:
An oblique aerial photograph is taken with the camera axis intentionally inclined from the vertical.
Such photographs provide a perspective view and exhibit varying scale.
Step 1: Understand oblique photography.
Characteristics include
• Tilted camera axis.
• Perspective view.
• Variable scale.
• Relief displacement.
Step 2: Identify the correct characteristic.
Hence,
\[
\boxed{\text{An oblique photograph is characterised by a tilted camera axis}.}
\]
Therefore, the correct option is
\[
\boxed{(A).}
\]