Explanation:

- The sentence discusses how the new software aids with complex issues like pick-up and delivery. This means the word relates to how these issues are connected or relevant to the software.

- Option 1: Promoting - This means to support or actively encourage something. It doesn’t fit the context of issues faced by pick-up and delivery tasks.

- Option 2: Denying - This means to refuse or withhold something. It doesn’t make sense as you’re not withholding issues in this context.

- Option 3: Trusting - This involves believing in someone’s reliability. It doesn’t align with discussing issues relating to tasks.

- Option 4: Referring - This means to mention or relate something. Here, it indicates the issues that are relevant or connected to pick-up and delivery activities.

The word "pertaining" most closely aligns with the idea of being related or connected to something.

- Correct Answer: Option 4 - Referring