While a relatively inefficient mode of transmission, accounts for 90% of hiv infections worldwide.

The correct answer is - sexual transmission.

Explanation:

HIV infections can be transmitted by the various mode. Sexual transmission is one of the major mode of transmission which is comprise almost 90 % of HIV infection, according to the reports. These are relatively inefficient mode, unprotected or unnatural sex is the major mode for the HIV transmission worldwide. Cases are now comparatively less than when it was discovered due to awareness.

Thus, the correct answer is - sexual transmission.

the answer to your question is b

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.