Agnat-sized insect known as the asian citrus psyllid has been spreading a deadly plant disease, huanglongbing, through america's citrus groves. early attempts to contain the disease have failed, and it has become a major threat to the u. s. citrus industry. huanglongbing is caused by bacteria, candidatus liberibacter, which the asian citrus psyllids carry in their salivary glands. the bacteria infiltrate plants' circulatory systems, which then results in blockages that stop the flow of nutrients from leaves to roots. to slow huanglongbing, scientists have imported wasps from asia to prey on the psyllids, but they do not know how introducing yet another species might impact the fruit-growing habitats. the best long-term solution may be genetic modification, which faces a long and costly road to regulatory approval and public acceptance. in this case, citrus trees would be genetically altered to resist the attack of the psylids. what is a noted negative in using genetic engineering to solve this problem of the psylids damage to u. s. citrus crops? a) time and money b) lack of man-power c) danger to citrus crop d) death to beneficial insects