Which of the following $STDs$ is not caused by a bacterium?

In case of a person suffering from syphilis, the chancre formation occurs during

What complications can arise if sexually transmitted diseases (STDs) are not diagnosed and treated in time?
$I -$ Pelvic Inflammatory Disease $(PID)$,$II -$ Abortions,$III -$ Stillbirths
$IV -$ Ectopic pregnancies,$V -$ Infertility,$VI -$ Cancer of the reproductive tract

Which of the following cannot be considered a symptom of a female suffering from gonorrhea?

Incubation period of $Treponema \text{ } pallidum$ is about

Which of the following principles are used to prevent $STD$ infection?
$(i)$ Avoid sex with unknown partners
$(ii)$ Use condoms during coitus
$(iii)$ Blood transfusion
$(iv)$ All of these