The correct answer is: Only argument II is strong.
Argument I is weak because it is based on the assumption that joint families always ensure security and reduce the burden of work. However, this is not always the case. There are many cases where joint families can be quite stressful and can lead to conflict. Additionally, not everyone wants the security and reduced burden of work that a joint family can provide. Some people prefer the freedom and independence that a nuclear family can offer.
Argument II is strong because it is based on the fact that nuclear families do offer greater freedom. Nuclear families allow individuals to make their own decisions and live their own lives. They also allow for more privacy and personal space. This can be a major advantage for people who value these things.
Overall, argument II is stronger than argument I because it is based on a more accurate and relevant premise.