Aşağıdaki metni okuyun ve soruyu cevaplayın.
Scientists are currently developing new vaccines to fight various diseases. They are working hard in laboratories around the world. In the past, it took many years to develop a single vaccine, but now, with advanced technology, the process is much faster. For example, the polio vaccine was developed in the $1950$s, saving millions of lives. Today, researchers are focusing on new viruses and bacteria, trying to find effective solutions for global health challenges.
Metne göre, bilim insanları şu anda ne üzerinde çalışmaktadır?
A) Polio aşısı geliştirmek
B) Eski aşıları test etmek
C) Yeni aşılar geliştirmek
D) Laboratuvarları temizlemek
