The core difference between phishing and spear-phishing is: a. anti-virus software prevents phishing but not spear-phishing b.spear-phishing has more specific targets than phishing c. phishing attacks via email, spear-phishing attacks via infected webpages d. phishing attacks via email, spear-phishing attacks via social media e. phishing is an outside attack; spear-phishing is an internal security check