_______ country’s COVID vaccine could offer double protection against the virus if successful ?

a) United Kingdom 
b) United States of America
c) Italy
d) None of these

In a breakthrough, the UK COVID-19 trials have shown that the Oxford vaccine could offer ‘double protection’ against COVID-19. The researchers at the University of Oxford in the United Kingdom discovered during human trials that their vaccine could trigger an immune response that will provide a double defense against Coronavirus.