Adrian caught a virus while staying with his grandmother. a few years later, his mother and sister got the same virus. this virus could spread through touch and direct contact. however, adrian did not contract the virus this time, even though he was living with his mother and sister. why did he not get sick? adrian’s adaptive immunity remembered the antigens from the virus and gave him lifelong immunity to it. adrian’s innate immunity remembered the antigens from the virus and gave him lifelong immunity to it. adrian’s skin layer recognized the antigens and attacked them, which prevented the occurrence of the virus again. adrian’s innate immunity identified antibodies specific for the virus and targeted them against the antigen. adrian’s adaptive immunity produced a higher amount of specific antibodies for the antigen, preventing the virus. nextreset

The most appropriate answer would be the first option.

Adaptive immunity is a part of the immune system which protects our body against infectious agents with the help of  B lymphocytes and T lymphocytes.  

It is characterized by its memory that is, it creates the memory of a lifetime for particular antigen or pathogen once it has come across.

As Adrian caught the virus a few years ago his immune system had developed a memory for the virus.  

So, as soon as his body contracted the same virus his body recognizes it easily and produce quicker and higher amplitude immune response against it.

the limb fractures are among the most common fractures. open fractures are comparatively more dangerous. the injury patterns are dependent on many factors, such as the age of the person, and mechanism of the injury. the closed fractures of the limbs if left untreated may lead to a significant amount of the blood loss, which may be life-threatening for the person. approximately 1000-1500 ml of blood is lost in the close fracture of the femur, and 500-1000 ml of blood is lost in the closed fracture of lower part of the limbs.