## 2 Literature Review
In addition, this technique allows for scholars to examine complex structural and statistical models based on multi-levels, for example, mediating, moderating, and other complex links among constructs. _Questionnaire Development_: The current research developed a survey questionnaire, which was designed from literary works. A team of experts was arranged to finalize the questionnaire, including six professors and six professionals belonging to relevant areas of this work. Ideas from the experts helped to improve the questionnaire by removing contradicting constructs. Further, we assessed the experts' recommendations and finalized the questionnaire after modifications. All of the items on the scale were taken from the literature. For example, the EBPr construct has five adapted items [65; 66]; the SUP construct has five adjusted items [67]; the OPT concept has six adapted scale items [68]; and seven items were adapted for environmental sustainability [65]. Before data collection, we assured the participant's that the information collected during data collection would be confidential and asked them to return the filled questionnaire. The final questionnaire had two parts to record the responses from the participants. The first part of the last questionnaire records demographical information, such as gender, working experience, job specification, firm age, firm registration, firm size, and number of employees. The second portion of the final questionnaire records feedback on 23 scale items. A 5-point Likert scale (strongly agree = 5, agree = 4, neither agree nor disagree = 3, disagree = 2, and strongly disagree = 1) was employed for scale items. _Data collection_: In the current work, the elected population for sampling belonged to focal firms located in 21 cities in the Guangdong province of China (see Figure 2). Tian Yan Cha (China's national database) was analyzed to start a data collection procedure to generate a list of companies. For the unit of analysis, registered and active companies were elected from this national database. According to Figure 2, Shenzhen city has the highest number of important companies, with 294 responses. Before data collection, 35 online answers were gathered in order to pre-test analysis for moving forward. The results for the pre-test described that the reliability and factor loadings of the items were good and met the 0.70 threshold [69]. Data for the final analysis were based on 1214 samples. During data collection, we contacted companies through email and WeChat and visited them in person for a high response rate. The final responses show that the level of awareness for environmental sustainability is quite higher in males. Further, the 20-24 respondents are more aware than other age groups due to their higher interest in green environments. Similarly, therespondents who worked in \(<\)50 employee firms (small firms) are more aware because of the workload and focus of operational activities. The 2-4 year-old firms are more aware than other firms due to the competitive environment for sustainability administration. Finally, environmental sustainability awareness is also high for sole-ownership firms (see Table 1). In addition, the demographical information of the collected data is revealed in Figure 3. The report for gender explains that 45.3% were male and 54.7% were female out of 1214 samples. The statistics specified that, out of the final sample size, 52.39% of participants had sole ownership, 29.74% of respondents had partnerships-based investments in a company, 15.4% of respondents were employees/owners of a limited company, and 2.47% of respondents were working as a group sharing investment with a firm. A total of 30.89% of participants worked in \(<\)2 year-old firm, 35.50% of participants were engaged with a 2-4 year-old firm, 16.39% of respondents belonged to a 4 to 6 year-old company, 10.63% of respondents were working at a 6-8 year-old company, and 6.59% respondents worked in a \(>\)6 year-old firm.