Which of the following is considered as an appropriate plant extraction technique? 1. Thermolabile components of plants

[answerhappygod]

Which of the following is considered as an appropriate plant
extraction technique?
1. Thermolabile components of plants are best extracted by
reflux
2. Concentration and drying of extracts in vacuo are necessary to
ensure the stability of components
3. Polar bioactive components should be extracted from the plan
matrix using petroleum ether
4. Extraction should always utilize an equal solvent-sample ratio
regardless of the absorbing nature of the solvent matrix