If you delete cookies from googlesyndication.com:
a) You might see less relevant or repetitive ads since the previous data about your browsing habits and preferences will be lost.
b) You will not be opted out of seeing ads altogether, but they might be more generic.
c) Some websites may load slightly slower the first time after clearing cookies since they need to recreate certain elements.
d) If there are any websites where you have settings or preferences saved that rely on these cookies, you might have to reconfigure those settings.
It’s generally safe to clear these cookies if you’re concerned about privacy or if you believe they’re taking up too much space. The main consequence, as mentioned, is potentially seeing less tailored advertisements.