Which of the following statements about hepatitis$-B$ is incorrect?
It is one of the examples of $STD$
It is spread primarily by sexual contact, even by contaminated syringes and blood transfusion
It is $42$ nm enveloped virus containing $ss-RNA$ as the genetic material
Recombivax $HB$, vaccine is available to prevent hepatitis$-B$ infection
Who was the first scientist to estimate the human population
$NSEP$ stands for
The population of India at the time of Christ was approximately
$MTP$ is considered safe upto how many weeks of pregnancy?