The correct answer is:
d. Afferent lymphatics
Naïve lymphocytes enter the lymph nodes through a specialized type of blood vessel called afferent lymphatics. These vessels bring lymph fluid, along with antigens and naïve lymphocytes, into the lymph node from surrounding tissues. Within the lymph node, the naïve lymphocytes can encounter antigens and initiate an immune response if necessary. Efferent lymphatics, on the other hand, carry filtered lymph fluid out of the lymph node after it has been processed by immune cells.
Therefore, statement d is true as afferent lymphatics are responsible for the entry of naïve lymphocytes into the lymph nodes.
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#include
#include
#include
#include
#include "sem_pv.h"
int main(void)
{
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int pid,fd,semid,n;
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key=ftok(".",5);
semid=sem_init(key);
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