What does 'selective herbicide' refer to?

A selective herbicide is specifically designed to target certain weed species while leaving desirable plants, such as crops or ornamental plants, unharmed. This targeted approach allows for effective weed control without damaging the surrounding vegetation that is intended to thrive. This characteristic is important for maintaining the health of desired plants and is widely used in agricultural and landscaping practices to manage weed competition without adversely affecting beneficial plants.

The other options do not accurately define selective herbicides. Some herbicides may kill all plants indiscriminately, while general-purpose herbicides are not selective and can affect a wide range of plant species. Additionally, the safety of herbicides for human consumption does not determine their specificity or selectivity regarding plants. Thus, the description that focuses on targeting specific species while protecting others aligns with the definition of a selective herbicide.