Which is true of software bugs?
bugs can only be identified when error messages appear.
the number of bugs are reduced by careful attention to programming conventions.
bugs cannot cause long-term harm.
most software initially contains no bugs.

Only the second statement is true: The number of bugs are reduced by careful attention to programming conventions.

The number of bugs are reduced by careful attention to programming conventions.

Explanation:

The bugs can be reduced if the attention of the programmer is too good. Bugs does not mean a system created or system informed error. There can even be logical errors where it does not produce any error message but still it affects the result badly which sometime may or may not be noted for longer duration.

Bugs cannot cause long-term harm is false because unnoticed logical error might have affected long-term

Bugs can be identified only if error message appear – this is false when the error is logical

Most software initially contains no bugs – this is also falls, there might be few unnoticed error which is found during the live production.

a software system that is used for viewing and creating hypertext is a hypertext system.

i hope this .