The reason the medical community prefers to use the term "sexually transmitted infection" (STI) rather than "sexually transmitted disease" is because: a) infections don't always result in disease symptoms or signs b) the term "infection" tends to be less stigmatized than "disease," and may make it more likely for people to seek medical care c) infections may progress to become diseases, but only if the correct set of conditions exists to do so d) all of the above.