This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to control black spot on roses
Plant black spot resistant roses, as many beautiful rose varieties are resistant to the diseases and fungi.
Control black spot by not planting varieties that are prone to it. Maintenance of the resistant varieties is much less than those that fall victim to every rose disease.

Available options: [I] Check out red spot on rose hardiness markers. You can get a rise out of reds and pinks. [II] Specific lists of disease-resistant roses are online, and nurseries likely have their own list. All roses vary by region, so do a local check for varieties that grow best in your area. [III] What follows should be monitored closely and tested for diseases such as the fungus sincosamine and borrage, along with the other common common diseases and fungi. Non-infected plants should not be given pesticides, as they can eventually spread to other types of plants. [IV] If your roses produce to millions of flowers every year, then you can make it much more difficult to control both the deadly and beautiful ones. Spray the surface of each rose's base with an organic or water-based brine insoluble repellant.
The answer is:
[II]