At distant stage of fertilization spermatozoa move against fluid flow toward oocyte. What is the name of this addressed movement?

At distant stage of fertilization spermatozoa move against fluid flow toward oocyte. What is the name of this addressed movement?

1.  Thermotaxis


2.  Chemotaxis


3.  Capacitation


4.  Acrosomal reaction


5.  *Rheotaxis