Examples of infections caused by indirect transmission of disease agents include: vehicle-borne infections airborne infections vector-borne infections all of the above

All of the above are correct answers.
Infections can be transmitted directly or indirectly.
Direct contact includes events when an infected person exchanges body fluids with another person or spray of droplets during coughing and sneezing.
Indirect contact includes vehicle transmission (when a vehicle (or fomite) touches a person's body), air transmission (for example, by entering a room after someone with infection) and vector transmission (transmitted by the bite of infected arthropod species, like mosquito, for example).

The answer is d have a nice day