Solution:The appropriate objectives for a study comparing the stress levels of male and female students of class IX in government schools of Delhi should focus directly on quantifying and comparing these stress levels. Objective (a), to find out the scores attained by male and female students as per the scale used, is essential as it aims to measure stress quantitatively using a specific scale, providing a basis for comparison.
Objective (d), to compare mean scores of stress of male and female students of Delhi, directly addresses the comparative aspect of the study, aiming to identify any significant differences in stress levels between genders.
These objectives are both directly relevant to the study's focus on stress comparison and are quantitative in nature, making them suitable for statistically analyzing the data collected.
Other options, like studying the influence of gender and residential background (b), interaction among male and female (c), and correlation between stress levels (e), while potentially valuable, do not directly relate to the main purpose of measuring and comparing stress levels as described in the research question.