Answer:b. There is no way to filter out all illegal content but still allow access to constitutionally protected materials.
Step-by-step explanation:
Sometimes trying to filter out negative content may require extensive filtering which may even prevent access to materials which are useful and actual protected because filtering may include exception of certain words for example which shouldn't appear when one searches the internet however those word may also be used in a protected information which doesn't carry explicit and harmful information so it end up being difficult to filter these words out.