That the general terms and conditions on which preliminary approval was granted shall not be changed, including but not limited to use requirements; layouts and design standards for streets, curbs and sidewalks; lot size; yard dimensions and off-tract improvements; and, in the case of a site plan, any requirements peculiar to site plan approval pursuant to Section 25-19 of this chapter, except that nothing herein shall be construed to prevent the municipality from modifying by chapter such general terms and conditions or preliminary approval as relate to public health and safety;

That the applicant may submit for final approval on or before the expiration date of preliminary approval the whole or a section or sections of the preliminary subdivision plat or site plan, as the case may be;

That the applicant may apply for and the Planning Board may grant extensions on such preliminary approval for additional periods of at least one year but not to exceed a total extension of two years, provided that if the design standards have been revised by ordinance, such revised standards may govern.

In the case of a subdivision of or site plan for an area of 50 acres or more, the Planning Board may grant the rights referred to in paragraphs a, b, and c above for such period of time, longer than three years, as shall be determined by the Planning Board to be reasonable taking into consideration (1) the number of dwelling units and nonresidential floor area permissible under preliminary approval, (2) economic conditions, and (3) the comprehensiveness of the development. The applicant may apply for thereafter and the Planning Board may thereafter grant an extension to preliminary approval for such additional period of time as shall be determined by the Planning Board to be reasonable taking into consideration (1) the number of dwelling units and nonresidential floor area permissible under preliminary approval, and (2) the potential number of dwelling units and nonresidential floor area of the section or sections awaiting final approval, (3) economic conditions and (4) the comprehensiveness of the development; provided that if the design standards have been revised, such revised standard may govern.